# Tag Info

## Hot answers tagged .exr

18

With very large image resolutions Blender can run out of RAM. The operating system will then start using the hard disk for memory which is slow and will cause low CPU usage (swapping). To reduce memory usage for very high resolution renders: Enable Save Buffers in the Performance panel so Blender does not keep the full render in memory during render Render ...

10

There are a few things going on, here. Firstly, the z-depth is exactly the distance of each pixel from the camera. You can demonstrate this by setting the clipping planes of your camera to specific values, and then using your mouse to inspect the RGB values in the render result view (not the saved image). The closest pixels will be the same value as your ...

9

Explanation first: PNGs can't handle pixels that are emissive and transparent at the same time because PNG does not support associated alpha transparency. You are on the right track using EXR, what you need to understand is that EXRs are exported as linear information (meaning no "gamma curves" are applied to make them display nicely on a monitor). The ...

6

Question: How to match an EXR (linear scene-referred information) to a PNG (in display referred values with sRGB "gamma" curves) of the same image in resolve? The issue: Even though both images are generated from the same render layer in blender, they are going through different pipelines and the values don't match: The PNG is encoded with a gamma curve (...

5

Blender's depth map should work fine. I have tested it and I do get the right distance. How do you load the OpenEXR files? Not all OpenEXR readers are reliable. I have noticed that OpenCV can give inaccurate results (see https://github.com/opencv/opencv/issues/10114).

5

In Blender, use compositor's despeckle node to get rid of those. The threshold setting is very important, this should do: Then save the image as OpenEXR.

5

Photoshop and other software of its ilk are display referred imaging applications. While PS will load an EXR, it does not possess the quality of controls one requires to properly manipulate scene referred photographic imagery. To deal with a strictly display referred application and suffer as little quality loss as possible, save to a display referred ...

5

Correct. Due to a very unfortunate design decision, no matter whatever your view transforms are set to, the EXR will always be the unadjusted, scene referred values from the Cycles render buffer. In order to perform colour transforms from an OCIO configuration, you would need to perform this task externally using a tool such as ocioconvert from the OCIO ...

5

Workbench It is not that easy :) and in some cases just impossible. If you want to just make parts darker or brighter, there is a change you just dont notice, but it would be there. This "imperfection" comes from anti-aliased pixels generated on object edge to make them smooth. They consists partly from foreground color and partly from background ...

4

I will use nodes rather than code, since they are more visual, hence easier to understand. I will use the following example scene. Diffuse Walls (1, 1, 1) Emission (1, 1, 1) with 0.9 strength Emission (red / blue) with 32 strength Cube consiting equally of Diffuse, Glossy, Tranmissive and Scattered shaders (all with different colors) Rendering and saving ...

4

As noted in the comments: The filetype in the File Browser context can't be changed in the filename area. It has to be set in the dropdown menu in the Save As Image section.

4

According to the manual, the depth map is inverse linear (1/distance) from the camera clip start. so it depends on the "Clip start" camera setting it shouldn't be read straightforwardly as a distance map, but the distances should be easy to work out From what is written, it would appear that Z_{\rm map} = \frac{A}{(d-{\rm clip_{start}})}\quad\...

3

This appears to be a problem with a misunderstanding as to how to handle alpha. When pushing out alpha, raytracing engines use associated alpha, as only associated alpha represents both occlusion and emission. As a result, the alpha in those subpixel seams must not be composited using the standard compositing operation, but rather one of the alternate over ...

3

It was noted in the comments but in short, use Multilayer when you want to bundle multiple render passes in one file. It's worth noting that some programs can read EXR files, but not Multilayer EXR files. For this reason, I use OpenEXR for non-lossy high color depth renders, and pretty much don't use OpenEXR Multilayer. The main purpose of Multilayer is to ...

3

This is essentially just a matter of interpretation and intended meaning. When the depth reports 10000000000 it’s not actually intended to represent an actual distance, rather ‘infinity’ (but it’s a suitably large enough value to essentially be regarded as that) and so it represents the rays not actually hitting anything. The camera clipping distance is ...

3

Maximeroz has made available filmic config.ocio files for Nuke and also an explanation on how to set it up:- http://www.maximeroz.com/blog/#/filmic/ http://www.maximeroz.com/filmic-nuke https://github.com/maximeroz/filmic-blender/tree/dev/extra It is dated July and November 2017, so I don't know how current the information is. There is also a config ...

3

Separate the object you want to render by layer. Place the render object on layer 2. (e.g. Torus) Place the masking objects (all other objects) on layer 1. (e.g. Cube) Make both layers visible in the Scene's layers. Set the Layer to layer 2 in the render layers tab. Set the Mask Layer to layer 1 (or more) in the render layers tab. The objects on layer 1 ...

3

The first tutorial lists a number of different shaders that may have their own render pass. Cycles doesn't separate the render result based on the shader used, cycles uses node based materials that can combine many different shader types to get the final result. In cycles the passes that are available will each contain a portion of the scene that when ...

3

About cryptomattes The issue is not due to the rotation but to the alpha over node: which results in plain color image. If you change the node group by this: That allows to keep the image size from the mask, without considering it (multiplied by 0) but adds the rotated cryptomatte values. A simple test case file:

2

According to this bug report: "the problem is that even if you have PNG selected in the blend to be rendered, if you use the 'Download render results from Network', they will always come back as layered .exr files. You only get them as PNGs when you press 'get animation' button." Have you tried the Get Animation button instead? Or, according to ...

2

The values are scene referred. You require a view transform to map to the display referred range. If you choose to use the sub-optimal sRGB EOTF, you are losing a heck of a lot of dynamic range. You can use a much wider dynamic range for the scene referred to display referred transform if you wish. Ultimately it is always a creative decision. See Render ...

2

The general problem with EXR images, is that they don't really behave as a normal image (like PNG). A PNG has, for each color, a min value 00 and a max value FF. An EXR is just a mathematical value from 0 up to infinity for each pixel. So rather than using multiply (as you are doing, and which works for PNG images), you should use minimum (or maximum,...

2

You can change the color depth like this: image_settings = bpy.context.scene.render.image_settings image_settings.file_format = "OPEN_EXR" image_setting.color_depth = '32' Note that '32' is a string and not an integer/float. Then save the image like this: img = bpy.data.images['myImage'] # your image here img.save_render("C:\\Users\\daddy\\me\\Documents\\...

2

If Blender is crashing during super high-resolution render for whatever reason, consider using add-ons for precise region render, like blender-renderborder or accurate-render-border (not sure about their 2.8 compatibility) or with some python usage. Enabling Crop in render settings can also help. Then stich small chunks into one image in PS, Gimp or other ...

2

You can install additional environment lights from the preferences: after files are chosen: You can now selected them as new environment maps:

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